Simulation study of wave emission from the sheath edge in capacitively coupled discharges

There is an evidence of wave emission with a frequency near the electron plasma frequency i.e ωpe at the sheath edge in collisionless capacitive radio-frequency (RF) discharges. This is the result of a progressive failure of quasi-neutrality near the electron sheath edge. There is a possibility for this wave energy to be transferred to electron thermal energy by Landau damping or a related process, and this mechanism may contribute significantly to electron heating. This research work reports that the emission of waves is associated with a field reversal during the expanding phase of the sheath. Trapping of electrons near this reverse field region is observed. Our calculation shows that these waves are electron plasma waves. 1